Rudolph Kippenhahn Prize for Rainer Moll

Continuing a young but already well-established tradition at the Max
Planck Institute for Astrophysics, the former MPA director Rudolph
Kippenhahn came to the Institute at the end of May to personally award
this year’s Kippenhahn Prize to Rainer Moll, a former MPA
student who is now at the Max Planck Institute for Solar System
Research. The Kippenhahn prize recognises the best scientific paper
written by a student at the MPA and Moll received it for his paper
”Large jets from small-scale magnetic fields“, which
appeared in the journal Astronomy & Astrophysics in 2010.

In his paper, Moll presents a numerical study of magnetic cores
rotating inside a non-magnetic stellar envelope, investigating under
what conditions a magnetically powered jet is formed that can break
through the envelope. As the processes involved are very complex and
vary over a wide range of scales, Moll had to invent a new method for
his 3-dimensional, magneto-hydrodynamic simulations: In a numerical
grid, with which the flow can be followed over a factor of 1000 in
distance, it is possible to cover the full development of the unsteady
flow, including the strong magnetically driven instabilities evolving
inside it. The laudation particularly recognised Moll’s
inventiveness in problem definition, and in developing methods for
visualization and physical interpretation of the complex 3-dimensional
results.

While Rudolph Kippenhahn remembered that the question about quasars
with a jet perpendicular to the disk started when he was ”still
in business“ — he was MPA director from 1975 to 1991
— the first explanations did not include anything about magnetic
fields, and he congratulated Moll for his study leading to ”one
of the first reasonable explanations“. However, Kippenhahn also
said that because of recent events, he looked more carefully at this
paper. Allowing for the fact that it is difficult in astronomy to copy
from a newspaper and get a PhD, he told Moll that even if it turned
out that he had copied from the Süddeutsche Zeitung, he could keep his
prize, as this was not part of the formal requirements.